1. Field of the Invention
Embodiments of the present invention relate generally to wireless digital communication and more specifically to a system and method for setting a path to an access point across a wireless mesh network.
2. Description of the Related Art
A conventional wireless mesh network includes a plurality of nodes, each incorporating a network interface. A given node may transmit payload data to one or more neighboring nodes via the network interface. The node may originate the payload data or forward the payload data on behalf of one or more other nodes.
The wireless mesh network may include an arbitrary number of nodes and may include certain access points, configured to bridge data communications within the mesh network to a related service system, such as a wire line or optical communications network. A given node may send its payload data directly to a particular access point or may forward payload data to the access point on behalf of one or more other nodes within the wireless mesh network. Thus, each node is capable of sending data to the access point via a direct path or via one or more indirect paths (e.g. by way of intermediate nodes configured to forward received payload data). The access point collects payload data for various nodes within the wireless mesh network and then forwards the payload data to the related service system through some form of system network such as a wide-area network (WAN).
In a conventional mesh network, each node has many different neighboring nodes and may send payload data to a particular access point by way of one of those neighboring nodes. Each of those neighboring nodes uses a particular path across the wireless mesh network to the access point, and each such path has an associated cost value based on, e.g., a number of hops to reach the access point, among other possible metrics. A given node typically selects the path having the lowest cost value, and then sends payload data to the neighboring node associated with that path.
A given node may also receive advertisements from neighboring nodes, where an advertisement received from a particular neighboring node specifies the cost value of the path used by that neighboring node. In situations where a node receives an advertisement for a path that has a cost value lower than the cost value of the current path, then the node may switch paths and begin sending payload data to the access point by way of the neighboring node and the corresponding path. In doing so, the node sends a re-registration to the access point via the newly selected path.
However, problems arise in situations where the re-registration process fails. When the node fails to re-register with the access point, that node has no valid paths and may be unreachable for a certain period of time. Unreachable nodes may severely affect the throughput of the wireless mesh network.
As the foregoing illustrates, what is needed in the art is an improved technique for switching paths in a wireless mesh network.